Similar to Red and Blue, Yellow arrived towards the end of the Game Boy's lifespan. It managed, though, to receive the title of second best-selling non-bundled game for its console, losing only to its predecessors.

Much like before, players journey across Kanto from their hometown, Pallet Town, defeating the eight Gym Leaders (Brock and Misty do not join the player, unlike in the anime) and eventually the Elite Four.

Blurb

You've finally been granted your Pokémon Trainer's license, and now you're on your way to becoming the world's greatest Pokémon Trainer! The shockingly-cute Pikachutags along behind you as you search the enormous world for monsters to train and evolve. Face off against Blastoise's torrential water cannons. Stand strong when facing Pidgeot's stormy Gust. Develop the ultimate Pokémon strategy to defeat the eight Gym Leaders and become the greatest Pokémon Master of all time!

Changes from Red, Green, and Blue

Aesthetic changes

The front Pokémon sprites have all been updated to resemble how they appear in their then-current Ken Sugimori artwork usually used in promotional images and strategy guides for the Japanese Red and Green, Japanese Blue, and the international Red and Blue, as well as some of them resembling how they appear in the anime. The back sprites are the same as the previous games.

Some Trainer sprites were also redone. Red and Blue now better resemble their stock artwork for Generation I, as the Pokémon sprites do. Brock wears an outfit like his anime counterpart's and Misty's bikini was changed to a shirt and shorts similar to those worn by hers, albeit without suspenders.

Kanto is slightly redesigned a second time, featuring different designs for doors, signposts, windows and other minor elements. The biggest overhaul was performed on Cerulean Cave, the game's final dungeon, where the layout was once more changed.

Furthermore, no other wild Pikachu can be found, thus requiring the player to trade a Pikachu from another Generation I game or Generation II game to obtain another one. A traded Pikachu will also not behave like the starter Pikachu, acting as a regular Pokémon instead (even to the point of being able to evolve with a Thunderstone), unless it matches the Original Trainer and Trainer ID number of the player.

Another Pikachu with the same Original Trainer and Trainer ID number as that of the player can be obtained by cheating. However, it will only behave like the starter Pikachu if the original one is released. Furthermore, if one of the new Pikachu is released, the Pikachu behaving like the starter will have a disappointment face for a limited period of time.

The cry of the starter Pikachu, or any Pikachu with the same OT and Trainer ID number of the player for that matter, is changed to "Pika!" when going in battle, "Chaaaaa!" if it faints, or "Pikachu!" on the status screen, instead of the original Pikachu cry.

The rival will eventually evolve his Eevee (and thus affect which are the other members of his party) depending on the player's actions early in the game:

Level-up learnsets and TM compatibility are altered slightly for certain Pokémon. Charizard, for example, can now learn Fly via HM02.

A minimal friendship system is implemented to track how Pikachu feels about the player and Pikachu will refuse to evolve. This would later be revamped in Generation II, where the system is vastly improved and applies to all Pokémon.

Enhanced compatibility with the Game Boy Color is present outside of Japan, providing color palette changes as the player switches locations, whereas the Japanese version is similar to the previous main seriesGeneration I games in where it only has Super Game Boy support. The ability to print out Pokédex entries using the Game Boy Printer was also implemented in every regional release.

The Super Game Boy palettes used for the Pokémon sprites are also lighter.

Several glitches were disabled, and all glitch Pokémon were altered because the data which was read incorrectly to create them had changed.

The location and availability of some Wild Pokémon allows the player to experience the game in a manner similar to the anime.

In the anime, Ash catches a Caterpie and a Pidgeotto in Viridian Forest. This is reflected in-game as Caterpie (but not Weedle) and Pidgeotto are both available in Viridian Forest for the player to catch. This is the only instance in Generation I where a Pidgeotto can be caught at a level earlier than Pidgey would evolve into it.

The Pokémon that Team Rocket use (Koffing, Ekans, Meowth and their evolutions) are not available to be caught in the wild. It would be unlikely that Ash would catch these Pokémon in the anime as they are the primary antagonists.

Wild Pikachu and Raichu are not available, as Pikachu is the player's starter Pokémon (furthermore, it is unlikely that Ash would catch another Pikachu or a Raichu).

Pokémon unobtainable in Yellow

The following Pokémon are not obtainable in Yellow. In order to obtain any of the below Pokémon, they must be traded from one of the previous Generation I games, or from the Generation II games, which has that Pokémon available, which will be indicated.

Connectivity

As well as reprising the ability to allow players to trade Pokémon between two cartridges via a Game Boylink cable, Yellow also debuted a new link battle mode, Colosseum 2. While battling another player's Pokémon team had been possible since the release of the Japanese Red and Green two years before Yellow's release, Yellow introduced several regulations in Colosseum 2 mode. Battle modes introduced include the Pika Cup (for Pokémon between Levels 15 to 20 only; their combined level limit is 50), Petit Cup (for Pokémon between Levels 15 to 20, heights under 6'8" (2m), and weights less than 44.1 lbs (20 kg) only) and Poké Cup (for Pokémon between Levels 50 to 55 only, and the sum of all entered Pokémon's Levels cannot exceed 155. Mew is not allowed). These three cups would later become standard cups in Stadium.

Reception

Like Red and Blue, Yellow was also well received by the press. Like its predecessors, it received a perfect 10/10 "Masterful" rating from IGN.[5] However, it was criticized as being "just a stopgap to help us wait for the real sequels".[6] Yellow received a slightly lower average score than Red and Blue of about 85% on GameRankings. Despite this, it was the site's top rated Game Boy game in the year of its release, 1999.[7]

Comparison to the anime

The game is loosely based on the original anime series, but has several differences:

English title

An English version game cartridge of Yellow

While the game's title has become widely accepted as simply Pokémon Yellow, its officially recognized name outside of Japan is not entirely certain. On the boxart for most English versions, the expression Special Pikachu Edition replaces the series' then-current slogan Gotta Catch 'em All! below the Pokémon logo, while Yellow Version is at the bottom, near where Red and Blue had theirs. However, the expression Special Pikachu Edition is repeated on the box's opening and spine.

Despite this, the instruction manual refers to the game as "the Yellow version of Pokémon", the player has the option of being called Yellow, following the trends of the other versions, and Yellow Version can be seen at the game's title screen.

Trivia

The opening of Yellow features the fewest number of Pokémon out of all main series games, fittingly showing onlyPikachu.

This is the only Generation I game in Japanese where a message describing the current progress of a save in course appears, unlike the international versions, where such behavior is present in all games of the generation.